Suppositories and pessaries: Definition, advantages and disadvantages, types of base, method of preparation, Displacement value and evaluation

1. Presented By:
Mrs. Priyanka Kandhare patil
Assistant Professor
Department of Pharmaceutics,
Bharatividyapeeth Poona College of Pharmacy
Erandwane Pune-411038, Maharashtra, India
E-mail:priyanka.kandhare@bharatividyapeeth.edu
Suppositories and pessaries

2. - Suppositories are solid dosage form of medicament for
insertion into body cavities other than mouth.
- They may be inserted into rectum, vagina or nasal cavity.
- The medicament is incorporated into the suppository base
and the product is formulated in such a way that they will
either melt or dissolve in the body cavity fluid to release the
medicament.
- Suppositories intended for vagina, urethra, ear or nose or
nasal cavity are also referred to as pessaries.
Advantages:
- They can be easily administered to the children, old persons
and to unconscious patients who cannot swallow the drug
easily.
- These are the convenient mode of administration of drugs
which irritate GIT, cause vomiting and destroyed in acidic
pH of the gastric juice of the stomach.

3. Disadvantages:
- The irritant drugs cant be administered by this route.
- These cannot be prepared easily.
- The suppositories are required to be stored at low temperature
ranging from 10 to 200C. These are required to be stored in
refrigerator, which is costly for poor patients.
Suppository bases:
The following are the ideal characteristics of the suppository bases;
- The base should produce a suppository that can retain its shape
for insertion at room temperature.
- It should melt at body temperature or dissolve or disperse in body
fluids.
- It should release the medicament readily.
- It should be nontoxic and nonirritant to the mucous membrane.
- It should be stable on storage.

4. Formulation of Suppositories
• Bases should be exist in solid form at room
temperature.
• It should not irritate and produced inflamed sensation in
body cavity.
• It should be stable during storage condition , No change
in colour, shape ,odour.
• It should retain hardness and shape during
manufacturing and handling.
• It should not reacts with drugs and additives.
• It should have good emulsifying and wetting property.
• It should have acid value less than 0.2 or zero.
• It should have iodine value less than 7.

5. Classification of Suppositories

6. According to route of administration
a. Rectal suppositories for adults weigh 2 gm and
are torpedo shape.
⦁ Children's suppositories weigh about 1 gm.
b. Vaginal suppositories or Pessaries weigh about 3-
5gm and are molded in globular or oviform shape or
compressed on a tablet press into conical shapes.
c. Urethral suppositories called bougies are pencil
shape. Those intended for males weigh 4 gm each and
are 100-150 mm long.
⦁ those for females are 2 gm each and 60-75 mm in
length.

7. Conti…
d. Nasal suppositories: called nasal bougies or buginaria
meant for introduction in to nasal cavity.
⦁ They are prepared with glycerogelatin base.
• They weigh about 1 gm and length 9-10 cm.
e. Ear cones:
⦁ Aurinaria and meant for introduction into ear.
⦁ Rarely used
⦁ Theobroma oil is used as base.
⦁ Prepared in urethral bougies mould and cut according to
size.

8. Types of bases:
1) Oleaginous bases:
a) Cocoa butter
b) Cocoa butter substitutes or synthetic fats.
- These bases melt at body temperature to release the
medicament.
2) Hydrophilic bases:
a) Water soluble bases:
Eg: gelato glycerin, soap glycerin and macrogol bases.
b) Water dispersible bases:
Eg: Emulsifying bases.
- These bases are either soluble or dispersible in body cavities.

9. 1) Oleaginous bases:
a) Cocoa butter (Theobroma oil):
- Cocoa butter or Theobroma oil
triglyceride.
is naturally occurring
- It is yellowish white solid obtained from crushed and roasted
seeds of Theobroma cocoa.
- It has butter like consistency having melting point of 30-
350C.
- Theobroma oil melts at body temperature and release the
medicament for rapid absorption.
- It is considered as most suitable base for rectal suppositories
but not suitable for pessaries because after melting it has a
tendency to leak out of the cavities and also it is immiscible
with mucous secretions.
- It is readily liquefy on warming and quickly settle on
cooling.

10. Limitations of cocoa butter:
Cocoa butter has most of the qualities of an ideal suppository
base but still, it has a number of serious disadvantages which
are as follows.
- It shows the phenomenon of polymorphism i.e. when cocoa
butter is melted and cooled it gets solidified into different
crystalline forms depending upon melting temperature, rate of
cooling and size of the mass.
- It becomes rancid and melts in warm weather.
- It has a tendency to stick to the sides of the mould when
solidified.
- The leakage from body cavities on melting can take place.
- It is relatively costly.
- It is immiscible with body fluids.

11. b) Synthetic fatty bases:
1) Emulsified Theobroma oil:
- This may be used as a base when large quantities of aqueous
solutions are to be incorporated.
- The use of 5% glyceryl monostearate, 10% lenette wax, 2-3%
cetyl alcohol, 4% beeswax and 12% spermaceti is recommended to
prepare Theobroma oil suppositories.
2) Hydrogenated oils:
- These are obtained by hydrogenation of various vegetable oils,
such as arachis oil, cotton seed oil, coconut oil, palm oil etc.
- It is used as substitute for Theobroma oil because it has number
of advantages over Theobroma oil;
These are;
- They are resistant to oxidation.
- Lubrication of the mould is not required.
- They produce colorless, odorless and elegant suppositories.

12. 2) Hydrophilic bases:
- Process of drug release from these bases is a function of
dissolution of base rather than its melting.
- Due to higher melting point of hydrophilic bases, problems of
compounding, handling and storage can be effectively reduced.
- The hydrophilic nature also contribute to drug release and its
absorption.
a) Water soluble bases:
These are of two types, gelled glycerin bases and macrogol bases.
1) Gelled glycerin bases:
- Glycerin is gelled either with soap or gelatin to produce base of
desired viscosity, softness or stiffness.
- These bases are water soluble and dissolved in body fluids to
release the medicament.
- The suppositories prepared from gelato-glycerin base are
translucent which tends to dissolve slowly in the body cavity.

13. - Glycero gelatin base is well suited for suppositories containing
boric acid, iodoform, iodides etc.
- Glycerin suppository containing 91% of glycerin gelled with
9% sodium stearate soap is official in USP, which is used to
evacuate the lower bowel.
- The formula for glycero gelatin suppositories IP contains
16%w/w gelatin and 70%w/w glycerin.
- The USP formula recommends 20% w/w of gelatin together
with 70% w/w glycerin.
Glycerin suppository bases have following limitation.
- Hygroscopic nature of glycerin suppositories bases may cause
irritation of rectal mucosa due to their dehydration effect. Their
hydrophillic nature also necessitates careful storage of
suppositories.
- Gelatin is incompatible with many drugs like tannic acid, ferric
chloride etc.
- There are more chances of bacterial and mould growth
therefore a suitable preservative is required.

14. - Preparation of these bases is time consuming and they have
tendency to sticks to moulds which necessitates mould lubrication.
2) Macrogol bases:
- Macrogol, polyethylene glycol or Carbowaxes have been
commonly used as water soluble bases for preparation of both
ointments and suppositories.
- The macrogols having molecular weight less than 1000 are liquids
and those with mol.wt more than 1000 are wax like solids.
- Due to their hygroscopic nature PEG bases may dehydrate the
mucosa and produce irritation.
- To reduce such discomfort these bases are usually dipped in water
before insertion.
Advantages of macrogol bases:
- They are chemically stable.
- They are nonirritant.
- They have good solvent properties.
- They are physiologically inert.

15. Disadvantage of macrogol base:
- They are hygroscopic, they may cause irritation after insertion
and hence require special storage conditions to store them.
- They are incompatible with certain drugs like tannins, phenols
etc.
b) Water dispersible bases:
- Water dispersible bases include several nonionic surfactants like
tween and span.
- They act as emulsifying agent in water, forming soft, bulky and
nonirritant emulsion suitable for rectal treatment.
They satisfy most of the criteria of an ideal base such as;
- Temperature stability.
- Drug compatibility.
- Nontoxicity, nongreasy.
- Resistant to microbial growth.
They increase the contact of medicament with the mucous
membrane by forming emulsion at the base-body fluid interface.

16. Other additives:
The nonionic surfactants due to their nontoxicity are used to
improve dispersion of drug.
Surfactants also change permeation of mucous membrane,
improving drug absorption.
The presence of soothing agents such as glycerin, PG, castor
oil minimizes irritation of mucosa.
The oil soluble antioxidants such as BHT, BHA are suitable
for oily bases.
Preservatives are more important in preparations containing
water.
Benzoic acid, sorbic acid, methyl and propyl parabens are
common preservatives.

17. Compounding of suppositories:
Suppositories can be compounded by one of the following method:
1. Moulding
2. Hand rolling
3. Compression.
4. Moulding:
a) Cocoa butter suppositories:
- In this method medicament is dissolved, suspended or emulsified in
a melted base and the mixture is poured into mould cavities to
solidify.
Suppository mould:
- The suppository mould of various types and sizes are available in
market for commercial use.
- The moulds are generally made up of stainless steel, nickel, copper
alloy, aluminium or plastic.
- Teflon coated moulds are available to prevent interaction of metal
with medicament.

18. - The suppository mould can be opened longitudinally by
removing the screw in the center of the plates.
- The mould is open at the time of cleansing, lubrication and
removal of suppositories.
- The mould is cleaned by removing the plates and immersed
in hot water containing detergent.
- After washing with water mould is dried thoroughly.
- Then the lubricant is applied. Every care should be taken so
that the inner surface of the cavities of the mould do not have
any scratch otherwise suppositories with uneven surface will
be produced.
Steps in moulding method:
1. Cleaning of mould:
- The opened plates are cleaned with detergent in hot water,
wiped gently with soft cloth and dried thoroughly.

19. 2. Lubrication of the mould:
- The lubrication of the mould is essential in case cocoa butter or
glycerogelatin base is used for the preparation of suppositories for
easy removal.
- The best lubricant is one which is immiscible with the base and
which is able to provide a buffer film between the suppository
mass and the mould surface.
- For cocoa butter suppository a thin film of mineral oil is used.
- The lubricant should be applied with the help of brush. Cotton
wool should not be used because cotton fibers get detached from
it.
- Arachis oil, liquid paraffin may be used for glycerin suppository.
- After lubrication, the mould is closed and placed inverted so as to
drain excess of lubricant.
3. Calibration of mould:
- Generally a standard mould of 1gm capacity is used.
- Suppositories are formulated on weight basis but the mould
filling is based on capacity of cavity to hold specific volume of
base.

20. - Although the volume of base remains the same, the weight of the
final suppository prepared using the same mould varies from base to
base according to their specific gravity.
- For example specific gravity of coca butter and gelato- glycerin is
1 and 1.5 resp, and therefore weight of suppository prepared using
the same mould will not be the same.
- The capacity of mould should be determined by preparing blank
suppository using base, weighing the product and taking the mean
weight.
- If the calibration value of a particular mould for cocoa butter base
is available, the calibration value for glycerogelatin base can be
calculated by simply multiplying with 1.15.
4. Displacement value:
- The volume of suppository from a particular mould is uniform but
its weight will vary because the densities of the medicament usually
differ form the density of the base with which the mould was
calibrated.
- To prepare the suppository of uniform and accurate weight, the
displacement value of the medicament is taken into consideration.

21. - Displacement value is defined as the quantity of the drug
which displaces one part of the base.
- The displacement value of some of the medicament is;
Aminophyllin 1.5
Boric acid 1.5
Iodoform 4.0
Zinc oxide 5.0
5. Method of preparation (Melting of cocoa butter and
incorporation of medicament in cocoa butter):
- Thoroughly clean and lubricate the mould with a suitable
lubricant.
- Keep it on ice in the inverted position to cool and drain an
excess of the lubricant.
- The lubrication of the mould is not required in case the
emulsifying base or synthetic base is used.

22. - Heat the porcelain dish over water bath. To this add the
required quantity of cocoa butter or any other base after
taking into account the displacement value of medicament.
- Remove the porcelain dish from water bath, when two third
of the base melts and stir thoroughly until whole of the mass
melts.
- Place the weighed quantity of powdered medicament to be
incorporated with the suppository base on ointment tile. Pour
about half of the melted base over it. Mix it thoroughly with
a flexible spatula.
- Transfer the mixed mass to the porcelain dish and mixed so
that a homogenous mass is formed.
- Warm the dish over water bath for a few seconds with
constant stirring, so that mass becomes pourable.

23. 6. Pouring into mould cavities:
- Pour the melted mass into cavities of suppository mould. Kept
over the ice.
- Fill each cavity to overflowing, in order to prevent the formation
of hollows in the tops of the finished suppositories because cocoa
butter contracts on cooling and hollows are formed at the top of the
suppositories.
- The precaution must be taken while pouring the mass into the
cavities.
- It must be continuously stirred to ensure even distribution of the
medicament in all the suppositories.
7. Congealing:
- The well filled moulds are cooled slowly. When mass has just
solidified ,the excess is trimmed off with a sharp knife.
- After about half an hour the moulds are opened to remove the
suppositories.
- Whenever necessary slight pressure is applied on broad ends of
suppository for ejection.

24. 8. Polishing:
- The excess lubricant is removed from the surface of suppositories
by rolling them on filter paper or clean cloth.
A recent development in moulding involves the use of
disposable plastic moulds. The warm liquid is directly poured in
preshaped packs made of plastic and sealed.
- These do not need refrigeration during storage and transport.
Refrigeration of such packs just before use causes solidification of
suppositories in desired shape.
b) Glycerogelatin suppositories:
The basic moulding technique remains the same as that of cocoa
butter suppositories.
1. Calibration of mould
2. Lubrication of mould
3. Preparation of glycerogelatin mass:- gelatin is soaked in
purified water for about 10 minutes.
- Glycerin previously heated to 1000C is added and the mixture is
heated on water bath.

25. If necessary to adjust the weight hot purified water is added or
the mass is heated to evaporate the water.
4. Incorporation of medicament:
Soluble and thermostable medicaments are either mixed with a
little amount of water or glycerin before heating. The glycerin
or aqueous solutions containing drugs are added in
glycerogelatin mass before pouring in mould cavities.
If insoluble, the medicament is first triturated in a warm
mortar with sufficient glycerin and then mixed with
glycerogelatin mass before pouring into mould cavities.
As this suppositories are often used for vaginal or urethral
administration, they should be free from pathogenic
organisms.
5. Pouring into mould cavities:
6. Congealing and polishing:

26. 2) Hand rolling:
- This is the oldest and simplest method of preparing a
suppository.
- No elaborate equipment, heating and determination of
mould capacity is required.
- The soluble medicaments are dissolved in a small
amount of water and if necessary, mixed with small
amount of wool fat to facilitate easy incorporation into the
suppository base.

27. Conti…
- The powder of insoluble medicament is kneaded with the
grated cocoa butter using a mortar and pestle, until the
resultant mass is plastic and thoroughly blended.
- If desired fixed vegetable oil is added to make the mixture
more cohesive and plastic.
- The mass is then rolled into the cylindrical rod of the
desired length and diameter on a pill tile, which is predusted
with a starch.
- The rod is cut into portions and then one end of each
piece is made pointed.

28. 3) Compression method:
- The method is useful for thermolabile and insoluble drugs because
heating and stirring of the base with medicament is not required.
Steps in this method are;
- Cocoa butter is grated. The ingredients are mixed with an equal
quantity of grated cocoa butter. Add the remaining amount of grated
cocoa butter.
- The compression of the prepared mass is done on hand or
power operated compression machine.
- The prepared mass is placed in a cylinder and forced
through a narrow opening by means of a piston.
- The threads of mass passing into mould are compressed
until a homogeneous fused mass is formed.
- If necessary the suppositories are ejected by further
pressure.

29. Packaging and storage:
• Suppositories are usually packed in shallow partitioned
card board boxes which can hold them in upright position
an do not allow them to come in contact with each other.
• Many commercial suppositories are packed separately in
aluminum foil, paper , plastic or PVC polythene strip.
⦁ Glycerogelatin suppositories are often packed in
tightly closed screw capped glass containers.
Poorly packed suppositories may give rise to
staining, breakage or deformation by melting.
⦁ Both cocoa butter and glycerinated gelatin suppositories
stored preferably in a refrigerator.
⦁ Polyethylene glycol suppositories stored at usual room
temperature without the requirement of refrigeration

30. Testing of Suppositories
Uniformity of weight test:
In this test, the weight measurement is done for those suppositories
which are produced in the same mold. To maintain the uniformity of the
weight.
Melting Range test:
Macro-melting range: Here the time is measured that takes for the
entire suppository to melt when immersed in a constant temperature (37
degrees Celsius) in the water bath.
Micro-melting range: Here the melting range is measured in capillary
tubes for the oily or fat base only.

31. Pessaries
⦁ Pessaries are a type of suppository intended for
vaginal use.
⦁ pessary is a device that is placed into the
vagina to support the uterus or bladder and
rectum.
⦁ A pharmaceutical pessary is made by blending
drugs with a substance which dissolves at body
temperature.
⦁ The drugs will slowly leach through the porous
membrane of the vagina.
⦁ The larger size moulds are usually used in
the preparation of pessaries such as 4 g and
8 g moulds.
⦁ Pessaries are used almost exclusively for
local medication, the exception being
prostaglandin pessaries that do exert a
systemic effect.

32. British Pharmacopoeia (BP) definition
“ Pessaries are solid, single-dose preparations. They have various
shapes, usually ovoid, with a volume and consistency suitable
for insertion into the vagina. They contain one or more active
substances dispersed or dissolved in a suitable bases that may be
soluble or dispersible in water or may melt at body temperature.
Excipients such as diluents, adsorbents, surface-active agents,
lubricants, antimicrobial preservatives and colouring matter,
authorised by the competent authority, may be added, if
necessary.”

33. Advantages of pessaries :-
• A melting range of 30 -36°C (solid at room
temperature but melts in the body).
• Readily melted on warming, rapid setting on cooling.
• Miscible with many ingredients.
• Non-irritating.
Disadvantages of pessaries :-
• Installation may trigger defecation reaction.
• Diarrhea& disease states affect absorption.
• it can cause pain and may interfere with sexual
intercourse.
• Irritation and even damage inside the vagina.
• Passing a small amount of urine during exercise or
when you sneeze and cough.

34. Formulation of pessaries :-
• A pessary is a type of suppository that
is meant to be inserted into the vagina
for treatment of local or systemic
diseases, in folk medicine garlic bulb is
inserted into vagina for treatment of
candidiasis.
• The aim of this work is to formulate
and evaluate aqueous extract of garlic
as a pessary.
• The pessary was formulated using the
pouring method and cocoa butter as a
base.
• The formulated pessaries were
evaluated using physical appearance,
crushing strength test, disintegration
and dissolution times tests as well as
content uniformity.

35. Thank you…!